As suspected, your Hashi's has trashed your nutrient levels so it's important to address your gut/absorption problems as SlowDragon advised. The absorption issues need sorting so that nutrients can be absorbed, and levels need to be optimised so that thyroid hormone can work.
VIT D
With a level of 44.7 you need more than 800iu daily but your GP won't be able to prescribe it. The Vit D Council recommends 100-150nmol/L. You need 5000iu daily for 3 months then retest. When you've reached the recommended range then you'll need a maintenance dose which may be 2000iu daily, it's trial and error so it's recommended to retest once or twice a year to keep within the recommended range. You can do this with a private fingerprick blood spot test with City Assays vitamindtest.org.uk
D3 aids absorption of calcium from food and K2-MK7 directs the calcium to bones and teeth where it is needed and away from arteries and soft tissues where it can be deposited and cause problems.
D3 and K2 are fat soluble so should be taken with the fattiest meal of the day, D3 four hours away from thyroid meds.
Magnesium helps D3 to work and comes in different forms, check to see which would suit you best and as it's calming it's best taken in the evening, four hours away from thyroid meds naturalnews.com/046401_magn...
Check out the other cofactors too.
**
FERRITIN
Needs to be at least 70, preferably half way through it's range, for thyroid hormone to work. You can help raise your level by eating liver regularly, maximum 200g per week due to it's high Vit A content, and including lots of iron rich foods in your diet apjcn.nhri.org.tw/server/in...
You need to post on the Pernicious Anaemia Society forum for further advice healthunlocked.com/pasoc
You may need testing for Pernicious Anaemia which should be done before starting folic acid for the folate deficiency. You may need B12 injections and again B12 should be started before folic acid.
**
Considering how long you have been iron and Vit D deficient, and the fact that you are now folate deficient, I am at a loss to understand why your GP cannot see what's behind your symptoms. As you are taking nothing except a Vit D supplement, your GP is being negligent in ignoring your other deficiencies. You might want to ask your GP why they've been ignored. It might be preferable to see a different GP.
I don't think many people do, most people's reaction to the suggestion is either YUCK or EEWWWWW.
Generalising here but many of the younger generation don't cook from scratch very often for whatever reason, and it's likely to be the older generation - maybe 60 plus - that would cook liver. Shame really as it's classed as a superfood, is quick to cook and not at all expensive.
Content on HealthUnlocked does not replace the relationship between you and doctors or other healthcare professionals nor the advice you receive from them.
Never delay seeking advice or dialling emergency services because of something that you have read on HealthUnlocked.
Antibodies and vitamin/mineral levels 
Vitamin/mineral levels
Vitamin and mineral levels 
Vitamin/mineral levels 
